Login fails(14.04) and returns to login screen on my sudo machine, while login is suc

I am using a machine on a cluster with a shared filesystem.
On one of these machines I have a sudo account with ubuntu 14.04 installed.

The problem is that login fails and retus to login screen on my sudo machine, while login is successful on other machines that I don't have a sudo on. This means that the issue is specific to my machine, and unrelated to files on my homedir. Login also fails when I try to coect with a local user.

login is successful with tty mode. I tried

sudo apt-get install --reinstall ubuntu-desktop

Thank you